Charging Question

"1989 Merc 100 hp. At FT it ha

"1989 Merc 100 hp. At FT it has been charging at a max of 16.6 volts and at a idle 13.8 or so. Not to worried about the 13.8 but the high number. What is the normal range for a charging system on this motor? If it is over charging, is there a voltage reg on this that needs to be changed?"

"Brian, 16.6 is at the high en

"Brian, 16.6 is at the high end of what you could consider normal.

Merc's charging systems with "rectifiers" simply convert the AC produced by the charge stator into DC and rely on the BATTERY to act as the capacitor/regulator.

That's why it's important to run a Marine battery instead of a regular auto battery (which wasn't designed to handle "unregulated" power).

Between idle and about 4500 rpms you should see between 13.5-14.5 volts which would be (normal) - at wide open you can see higher (as you are in your case)..."